Methods and apparatuses for receiving and sending control channel

ABSTRACT

Embodiments of the present invention disclose methods and apparatuses for receiving and sending a control channel, and are applicable to the field of communications technologies. In the embodiments of the present invention, a base station carries scheduling information of a user equipment of an R11 system in both the PDCCH region and the E-PDCCH region of a downlink subframe. In this way, the user equipment needs to detect the control channel within the PDCCH region and the E-PDCCH region, so that resources of the two regions are available to the user equipment of the R11 system. Moreover, the user equipment detects only the control channel of the first type in the PDCCH region, and detects control channels of the other type in the E-PDCCH region. The method in the embodiments of the present invention does not increase the number of control channel detections.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/CN2012/079316, filed on Jul. 28, 2012, which claims priority toChinese Patent Application No. 201110213895.3, filed on Jul. 28, 2011.The afore-mentioned patent applications are hereby incorporated byreference in their entireties.

TECHNICAL FIELD

The present invention relates to the field of communicationstechnologies, and in particular, to methods and apparatuses forreceiving and sending a control channel.

BACKGROUND

In an existing Long Term Evolution (Long Term Evolution, LTE)communication system, a base station needs to send user equipmentscheduling information by using a downlink subframe. The time-frequencyresources of the downlink subframe are divided into two regions: aphysical downlink control channel (Physical Downlink Control Channel,PDCCH) region and a physical downlink data channel (Physical DownlinkShared CHannel, PDSCH) region. The PDCCH region is used to transmitdownlink or uplink data transmission scheduling indication signalingsent by a base station to a user equipment, including informationrelated to data channel resource allocation, a modulation and codingscheme, and a multi-antenna transmission or hybrid automatic repeatrequest (Hybrid Automatic Repeat Request, HARQ) process; and the PDSCHregion is used to carry specific scheduling data.

As shown in FIG. 1, in a downlink subframe, a PDSCH region and a PDCCHregion employ a time division multiplexing mode. The PDCCH region (thatis, the part filled with slashes in FIG. 1) occupies the first Northogonal frequency division multiplexing (Orthogonal FrequencyDivision Multiplexing, OFDM) symbols of the downlink subframe, where Nis dynamically variable and less than or equal to 3, and the PDSCHregion occupies the remaining OFDM symbols.

Scheduling information sent by a base station for multiple userequipments may be multiplexed in the PDCCH region in a subframe. ThePDCCH region corresponding to each user equipment may be composed of 1or 2 or 4 or 8 control channel elements (Control Channel Element, CCE).Such compositions correspond respectively to different coding rates. Inthis way, in the PDCCH region of the downlink subframe, CCEs make up thePDCCH region of different user equipments to carry the user equipmentscheduling information sent by the base station. When receiving adownlink subframe sent by the base station, a user equipment does notknow which CCEs make up a PDCCH region corresponding to the userequipment. Therefore, the user equipment needs to detect thecorresponding PDCCH region blindly in a common search space and aspecific search space. Specifically, the user equipment detects controlchannels of all possible CCE combinations (that is, 1 CCE, 2 CCEs, 4CCEs, and 8 CCEs) in the received downlink subframe until the PDCCHregion corresponding to the user equipment is detected.

To provide higher spectrum efficiency and cell edge user performance, inan evolved release (Release, R) system of an LTE system, that is, in anR11 system, coordinated multi-point (CoMP) and a more flexiblemultiple-input multiple-output (Multiple-Input Multiple-Output, MIMO)scheduling mechanism are introduced so that a cell can serve much moreuser equipments concurrently. Therefore, in a downlink subframe sent bythe base station, a PDCCH region with at most three OFDM symbols cannotmeet requirements of the R11 system, and a new PDCCH resource needs tobe defined, that is, an extended physical downlink control channel(Extended Physical Downlink Control Channel, E-PDCCH) region, which usesa part of time-frequency resources of the original PDSCH region and canbe multiplexed with the PDSCH region through frequency divisionmultiplexing or time-frequency division multiplexing.

To avoid increase of blind detection of control channels by a userequipment, an existing solution is to limit uplink and downlinkscheduling information of a user equipment of the R11 system to betransmitted by a base station only within an E-PDCCH region, so that theuser equipment needs only to perform blind detection of the E-PDCCHregion in a common search space and a specific search space. However, ina non-evolved release (R8/9/10) system of the LTE system, if thequantity of user equipments is small, the PDCCH region is not fullyoccupied, but the remaining PDCCH region resources are not available tothe user equipments in the R11 system, which leads to low resourceutilization.

SUMMARY

Embodiments of the present invention provide methods and apparatuses forreceiving and sending a control channel to increase the resourceutilization without increasing the number of control channel detections.

An embodiment of the present invention provides a method for receiving acontrol channel, including:

detecting a control channel of a first type within a physical downlinkcontrol channel PDCCH region; and

detecting a control channel of a second type within an evolved physicaldownlink control channel E-PDCCH region, where the control channel ofthe first type is different from the control channel of the second type.

An embodiment of the present invention provides a method for sending acontrol channel, including:

sending scheduling information over a control channel of a first typewithin a physical downlink control channel PDCCH region; and

sending scheduling information over a control channel of a second typewithin an evolved physical downlink control channel E-PDCCH region,where

the control channel of the first type is different from the controlchannel of the second type.

An embodiment of the present invention further provides a userequipment, including:

a first detecting unit, configured to detect a control channel of afirst type within a physical downlink control channel PDCCH region; and

a second detecting unit, configured to detect a control channel of asecond type within an evolved physical downlink control channel E-PDCCHregion, where the control channel of the first type is different fromthe control channel of the second type.

An embodiment of the present invention further provides a base station,including:

a first sending unit, configured to send scheduling information over acontrol channel of a first type within a physical downlink controlchannel PDCCH region; and

a second sending unit, configured to send scheduling information over acontrol channel of a second type within an evolved physical downlinkcontrol channel E-PDCCH region, where the control channel of the firsttype is different from the control channel of the second type.

As can be seen, in the embodiments of the present invention, the basestation carries scheduling information of a user equipment in an R11system in both the PDCCH region and the E-PDCCH region of a downlinksubframe. In this way, the user equipment needs to detect the controlchannel within the corresponding PDCCH region and E-PDCCH region, sothat resources of the two regions are available to the user equipment inthe R11 system. Moreover, in the embodiments of the present invention,control channels of different types are detected in the PDCCH region andthe E-PDCCH region, and therefore, only the control channel of the firsttype is detected in the PDCCH region, and a control channel of anothertype in a certain format is detected in the E-PDCCH region. In this way,compared with the fact that in the system of a non-evolved release, theuser equipment needs to detect control channels of all possible types,the method in the embodiments of the present invention does not increasethe number of control channel detections.

BRIEF DESCRIPTION OF DRAWINGS

To illustrate the technical solutions in the embodiments of the presentinvention or in the prior art more clearly, the following brieflyintroduces the accompanying drawings required for describing theembodiments or the prior art. Apparently, the accompanying drawings inthe following description show merely some embodiments of the presentinvention, and a person of ordinary skill in the art may still deriveother drawings from these accompanying drawings without creativeefforts.

FIG. 1 is a schematic structural diagram of a downlink subframe in theprior art;

FIG. 2 is a flowchart of a method for receiving a control channelaccording to an embodiment of the present invention;

FIG. 3a is a schematic structural diagram of a downlink subframeaccording to an embodiment of the present invention;

FIG. 3b is a schematic structural diagram of another downlink subframeaccording to an embodiment of the present invention;

FIG. 4 is a structural diagram of multiplexing scheduling informationsent by a base station for multiple user equipments into a PDCCH regionof a downlink subframe according to an embodiment of the presentinvention;

FIG. 5 is a structural diagram of an aggregation format of a PDCCHregion in a downlink subframe according to an embodiment of the presentinvention;

FIG. 6 is a flowchart of a method for sending a control channelaccording to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a user equipment accordingto an embodiment of the present invention; and

FIG. 8 is a schematic structural diagram of a base station according toan embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

The following clearly describes the technical solutions in theembodiments of the present invention with reference to the accompanyingdrawings in the embodiments of the present invention. Apparently, thedescribed embodiments are merely a part rather than all of theembodiments of the present invention. All other embodiments obtained bya person of ordinary skill in the art based on the embodiments of thepresent invention without creative efforts shall fall within theprotection scope of the present invention.

An embodiment of the present invention provides a method for receiving acontrol channel, applied to blind detection performed by a userequipment for the control channel in a process of receiving the controlchannel. The method in this embodiment is performed by a user equipmentin an R11 system. As shown in FIG. 2, the method includes the followingsteps:

Step 101: Detect a control channel of a first type within a physicaldownlink control channel PDCCH region.

Step 102: Detect a control channel of a second type within an evolvedphysical downlink control channel E-PDCCH region.

Understandably, a base station may carry uplink or downlink datatransmission scheduling information of a user equipment in a downlinksubframe and send it to the user equipment. In the embodiment of thepresent invention, the downlink subframe sent by the base stationincludes a PDCCH region, a PDSCH region, and an E-PDCCH region. ThePDSCH region and the PDCCH region employ a time division multiplexingmode, the PDCCH region occupies the first N OFDM symbols of the downlinksubframe, and the PDSCH region occupies the remaining OFDM symbols. TheE-PDCCH region uses a part of time-frequency resources of the originalPDSCH region, and can be multiplexed with the PDSCH region throughfrequency division multiplexing (as shown in FIG. 3a ), or multiplexedwith the PDSCH region through time-frequency division multiplexing (asshown in FIG. 3b ).

A basic composition unit of resources in a PDCCH region is CCE. Each CCEis mapped to a group of specific time-frequency lattices (ResourceElement, RE) in the PDCCH region. The scheduling information sent by thebase station for multiple user equipments may be multiplexed in thePDCCH region in a downlink subframe, and the PDCCH region correspondingto each user equipment may be composed of 1 or 2 or 4 or 8 CCEs. Forexample, as shown in FIG. 4, CCE 1 to CCE 4 make up a PDCCH regioncorresponding to user equipment (UE) 1, CCE 5 and CCE 6 make up a PDCCHregion corresponding to user equipment (UE) 2, and CCE 7 and CCE 8respectively make up a PDCCH region corresponding to user equipment 3and a PDCCH region corresponding to user equipment 4.

A basic composition unit of resources in an E-PDCCH region is evolvedCCE (E-CCE). Each E-CCE is mapped to a group of specific time-frequencylattices in the E-PDCCH region. The structure and the size of the E-CCEmay be the same as or different from the structure and the size of theCCE in the PDCCH region.

The base station carries user equipment scheduling information in thePDCCH region and the E-PDCCH region of the downlink subframe by usingcontrol channels of different types. For example, the base station usesa combination of N1 CCEs in the PDCCH region, and uses a combination ofN2 E-CCEs in the E-PDCCH region, to transmit scheduling indicationsignaling of downlink or uplink data transmission scheduled by the basestation for a specific user equipment. However, the user equipment doesnot know which control channel elements make up the PDCCH region and theE-PDCCH region that correspond to the user equipment, and therefore,when receiving the downlink subframe, the user equipment needs toblindly detect the PDCCH region and the E-PDCCH region that correspondto the user equipment. Therefore, when the user equipment performs theblind detection, the detected control channel of the first type isdifferent from the detected control channel of the second type.Specifically, at least one of multiple attributes varies between thecontrol channel of the first type and the control channel of the secondtype. The multiple attributes include: an aggregation format of thecontrol channel, a format of signaling transmitted over the controlchannel, a search space type of the control channel, and so on.

(1) The aggregation format of the control channel is a tree-structuredcombination mode of control channel elements. Specifically, as shown inFIG. 5, the control channel elements are numbered, and the PDCCH regionis composed of continuously numbered control channel elements. Thenumber of control channel elements composition (that is, level)represents the aggregation format of the control channel, expressed asfε{1, 2, 4, 8}. Therefore, each PDCCH region may be expressed as i*f(i=0, 1, 2 . . . ).

The control channel of the first type may cover at least one aggregationformat, and the control channel of the second type may also cover atleast one aggregation format. Therefore, difference between theaggregation format of the control channel of the first type and theaggregation format of the control channel of the second type means thatthe aggregation formats covered by the control channel of the first typeare completely or partially different from the aggregation formatscovered by the control channel of the second type; and, complete orpartial difference of the combination modes of control channel elementsdetected when the user equipment performs detection in the PDCCH regionand the E-PDCCH region includes complete or partial difference of thenumber of integral control channel elements (that is, an aggregationlevel of the control channel) and/or the format of the control channelelement, such as difference of the size or the structure of the controlchannel element.

(2) The format of signaling transmitted over the control channel refersto specific contents of the control channel for transmitting thescheduling information. If the format of signaling transmitted over thecontrol channel of the first type is different from the format ofsignaling transmitted over the control channel of the second type, thespecific contents of the control channels detected by the user equipmentin the PDCCH region and the E-PDCCH region are different. Specifically,the control channel detected by the user equipment in the PDCCH regionand the control channel detected in the E-PDCCH region transmit downlinkcontrol information of different downlink control signaling formats (DCIformat). The DCI formats specifically may include a first DCI formatgroup, a second DCI format group, a third DCI format group, and so on.The first DCI format group includes format a and format b, and thesecond DCI format groups include format c and format d.

(3) The search space type refers to a transmission resource range inwhich the user equipment searches for a downlink subframe, and includesa common search space type and a user-specific search space type. Thecommon search space is used to transmit scheduling indication signalingof common control information (such as a system broadcast message, apaging message, and an random access message), and the user-specificsearch space is used to transmit scheduling indication signaling ofuplink and downlink data transmission of the user equipment. Generally,the common search space includes control channel elements numbered 0 to15 fixedly, and the beginning of the user-specific search space dependson the user identifier (ID) and the PDCCH aggregation format. If thesearch space type differs between the control channel of the first typeand the control channel of the second type, the search space that coversthe control channel detected by the user equipment in the PDCCH regionis different from the search space that covers the control channeldetected by the user equipment in the E-PDCCH region.

It should be noted that the order between step 101 and step 102 is notdefinite, and the order shown in FIG. 2 is only a specific example.

As can be seen, in the embodiment of the present invention, the basestation carries scheduling information of a user equipment in an R11system in both the PDCCH region and the E-PDCCH region of a downlinksubframe. In this way, the user equipment needs to detect the controlchannel within the PDCCH region and E-PDCCH region respectively, so thatresources of the two regions are available to the user equipment in theR11 system. Moreover, in the embodiment of the present invention,control channels of different types are detected in the PDCCH region andthe E-PDCCH region respectively, and therefore, only the control channelof the first type is detected in the PDCCH region, and a control channelof another type is detected in the E-PDCCH region. In this way, comparedwith the fact that in the system of a non-evolved release, the userequipment needs to detect control channels of all possible types, themethod in the embodiment of the present invention does not increase thenumber of control channel detections.

It should be noted that a base station side may configure controlchannels of the first type and the second type to be detected by theuser equipment. The base station may send configuration information tothe user equipment in a predefined or broadcast manner. Theconfiguration information is used to indicate the control channels ofthe first type and the second type to be detected by the user equipment,and the configuration information may be sent by using a message such asa broadcast message or a high layer signaling notification.

Moreover, the base station may configure that the types of the controlchannel detected by multiple user equipments in the PDCCH region (orE-PDCCH region) are the same, or the types of the control channeldetected by user equipments in the PDCCH region (or E-PDCCH region) aredifferent.

In a specific embodiment, if the aggregation formats differ partly orfully between the control channel of the first type and the controlchannel of the second type, the aggregation formats covered by thecontrol channel of the first type detected by the user equipment in thePDCCH region are partly or fully different from the aggregation formatscovered by the control channel of the second type detected by the userequipment in the E-PDCCH region.

(1) If the aggregation formats of the control channels are fullydifferent:

Assume that there are N aggregation formats of the control channel, thatis, {f₀, f₁, f₂, . . . , F_(N-1)}, in the PDCCH region, a controlchannel may be composed of f_(i) (i=0, . . . , N−1) CCEs and in theE-PDCCH region, a control channel may be composed of f_(i) (i=0, . . . ,N−1) E-CCEs. Therefore, when performing detection in the PDCCH region,the user equipment detects control channels whose aggregation format isf_(i) (0≦i≦N₁); and when performing detection in the E-PDCCH region, theuser equipment detects control channels whose aggregation format isf_(i) (N₁<i≦N).

Moreover, in the aggregation formats f_(i) of the control channelsdetected by the user equipment, i may be any one or more values from 0to N, and the i values applied in the detection in the PDCCH region donot intersect the i values applied in the detection in the E-PDCCHregion.

For example, Table 1 below shows the control channel of the first typeand the control channel of the second type that have fully differentaggregation formats, and therefore, the user equipment in the R11 systemdetects, in the PDCCH region, control channels whose aggregation formatis {1*CCE, 2*CCE}, and the number of detections is N1+N2; and the userequipment detects, in the E-PDCCH region, control channels whoseaggregation format is {4*E-CCE, 8*E-CCE}, and the number of detectionsis N3+N4. Therefore, the total number of detections performed by theuser equipment in the R11 system in the PDCCH region and the E-PDCCHregion is N1+N2+N3+N4, and is not more than the number of detections ofthe control channels of the aggregation formats {2*CCE, 1*CCE, 4*CCE,8*CCE} in the PDCCH region by a user equipment in a system of anon-evolved release.

TABLE 1 Common and user-specific search space Control Number of TypeAggregation level channel element detections Control channel 1 CCE N1 offirst type 2 CCE N2 Control channel 4 E-CCE N3 of second type 8 E-CCE N4

(2) To further improve flexibility of allocating PDCCH resources, theaggregation formats covered by the control channels detected in thePDCCH region and the E-PDCCH region, that is, the combination mode ofthe control channel elements, may be partly different. Therefore, thesum of the number of detections of the control channel of the first typein the PDCCH region by the user equipment and the number of detectionsof the control channel of the second type in the E-PDCCH region isrequired to be not greater than the preset number of detections.

Specifically, when performing detection in the PDCCH region, the userequipment detects control channels whose aggregation format is f_(i)(0≦i≦N₁); when performing detection in the E-PDCCH region, the userequipment detects control channels whose aggregation format is f_(i)(N₂≦i≦N), where N₂<N1. To avoid increase of the number of detections,assuming that the control channel of the first type is detected for M1times in the PDCCH region and the control channel of the second type isdetected for M2 times in the E-PDCCH region, M1+M2 is not greater thanthe preset number M of detections, where M may be the number ofdetections of the control channel in the PDCCH region by a userequipment in a system of a non-evolved release (a user equipment in theR8/9/10 system).

Moreover, in the aggregation formats f_(i) of the control channeldetected by the user equipment, i may be any one or more values from 0to N, and the i values applied in the detection in the PDCCH regionintersect the i values applied in the detection in the E-PDCCH region.

For example, Table 2 below shows the control channel of the first typeand the control channel of the second type that have partly differentaggregation formats, and therefore, the user equipment in the R11 systemdetects, in the PDCCH region, control channels whose aggregation formatis {1*CCE, 2*CCE}, and the number of detections is X1+X2; and the userequipment detects, in the E-PDCCH region, control channels whoseaggregation format is {2*E-CCE, 4*E-CCE}, and the number of detectionsis X3+X4. Therefore, the total number of detections performed by theuser equipment in the R11 system in the PDCCH region and the E-PDCCHregion is X3+X4+X1+X2, and, if the sum of the numbers of detections,M1+M2, is not greater than the preset number M of detections, is alsonot more than the number of detections of the control channels of theaggregation formats {2*CCE, 1*CCE, 4*CCE, 8*CCE} in the PDCCH region bya user equipment in a system of a non-evolved release.

TABLE 2 Common and user-specific search space Control Number of TypeAggregation level channel element detections Control channel 1 CCE X1 offirst type 2 CCE X2 Control channel 2 E-CCE X3 of second type 4 E-CCE X4

Because the E-PDCCH region uses the resources of the original PDSCHregion, the available resources are sufficient, a dedicated pilot may beused for demodulation and multi-antenna transmission, and thetransmission performance is better than the transmission performance ofthe PDCCH region. Therefore, the size of the resources of theaggregation formats covered by the control channel of the second typedetected by the user equipment in the E-PDCCH region is not smaller thanthe size of the resources of the aggregation formats covered by thecontrol channel of the first type detected in the PDCCH region, therebyfurther improving control channel performance and resource utilization.For example, the aggregation formats of the control channel include {1,2, 4, 8}, and therefore, the user equipment may detect control channelswhose aggregation format is {1, 2} in the PDCCH region, the userequipment may detect control channels whose aggregation format is {4, 8}in the E-PDCCH region.

It should be noted that the aggregation format of the control channelsdetected by the user equipment in the PDCCH region and the E-PDCCHregion may be a common configuration of a cell, that is, a base stationmay configure all user equipments to detect control channels of the sameaggregation format in the PDCCH region (or E-PDCCH region), and sendconfiguration information to the user equipments through a predefinedmanner of the system or a broadcast message.

The base station may also configure each user equipment to detectcontrol channels of different aggregation formats in the PDCCH region(or E-PDCCH region). For example, the base station may configure userequipment 1 to detect control channels of the aggregation formats 1 and2 in the PDCCH region, and detect control channels of the aggregationformats 4 and 8 in the E-PDCCH region; and, the base station mayconfigure user equipment 2 to detect the control channels of theaggregation format 1 in the PDCCH region, and detect the controlchannels of the aggregation formats 2, 4, and 8 in the E-PDCCH region.

When configuring the aggregation format of the control channel to bedetected by the user equipment, the base station may notify the userequipment of the configuration by using high layer signaling.Specifically, the high layer signaling notification may bind theaggregation format of the control channel to an identifier (ID) of theuser equipment. For example, there are S control channel aggregationformats, and a user equipment may be configured to detect the controlchannel of the s^(th) aggregation format, where s is the identifier ofthe user equipment modulo S, that is, s=mod(UE_ID, S).

In addition, the configuration information may be sent by the basestation to the user equipment through user equipment-specific(UE-specific) signaling or cell-specific (cell-specific) signaling.

In another specific embodiment, if the format of signaling transmittedover the control channel of the first type is different from the formatof signaling transmitted over the control channel of the second type,the DCI format of downlink control information transmitted over thecontrol channel detected by the user equipment in the PDCCH region isdifferent from the DCI format of downlink control informationtransmitted over the control channel detected in the E-PDCCH region.

For example, the DCI format of downlink control information transmittedover the control channel of the first type detected by the userequipment in the PDCCH region is an uplink scheduling UL_grant controlsignaling format, but the DCI format of downlink control informationtransmitted over the control channel of the second type detected in theE-PDCCH region is a downlink scheduling DL_grant control signalingformat; or, the DCI format of downlink control information transmittedover the control channel of the first type detected by the userequipment in the PDCCH region is a downlink scheduling DL_grant controlsignaling format, but the DCI format of downlink control informationtransmitted over the control channel of the second type detected by theuser equipment in the E-PDCCH region is an uplink scheduling UL_grantcontrol signaling format.

In addition, if the two types of DCI formats are equal in size, the DCIformats of downlink control information transmitted over the controlchannel of the first type detected in the PDCCH region include one ofthe two types of the DCI formats, and the DCI formats of downlinkcontrol information transmitted over the control channel of the secondtype detected in the E-PDCCH region include the other type of the DCIformats. In this way, it is ensured that the downlink controlinformation transmitted over the control channel of the first typeincludes multiple control signaling formats DCI format of differentsizes, and that the downlink control information transmitted over thecontrol channel of the second type includes multiple control signalingformats DCI format of different sizes.

Specifically, assume that there are M formats of signaling transmittedover the control channel, that is, {g₀, g₁, g₂, . . . , g_(N-1)}. In thePDCCH region, a control channel may be composed of f₁ (g_(i)) CCEs; and,in the E-PDCCH region, a control channel may be composed of f₂ (g_(i))E-CCEs. Therefore, the format of signaling transmitted over the controlchannel detected by the user equipment in the PDCCH region is differentfrom the format of signaling transmitted over the control channeldetected in the E-PDCCH region. For example, the control channeldetected by the user equipment in the PDCCH region transmits informationof a f₁ (g_(i)) format, and the control channel detected in the E-PDCCHregion transmits information of a f₂ (g_(i)) format.

It should be noted that the format of signaling transmitted over thecontrol channels of the first type and the second type detected in thePDCCH region and the E-PDCCH region may be a common configuration of acell, that is, the control signaling formats covered by the controlchannel of the first type and the control signaling formats covered bythe control channel of the second type may be a common configuration ofthe cell. In this case, for all user equipments in the cell, the controlsignaling formats covered by the control channel of the first type arethe same, and the control signaling formats covered by the controlchannel of the second type are also the same. Such a configuration maybe predefined, or the configuration information is sent to the userequipment through a system broadcast message.

The base station may also configure the control signaling formatscovered by the control channel detected by each user equipment in theE-PDCCH region (or PDCCH region) to be different. For example, userequipment 1 detects control channels that cover DCI format 1 and DCIformat 1A in the PDCCH region, and detects control channels that coverDCI format 2C and DCI format 2D in the E-PDCCH region; and, userequipment 2 detects control channels that cover DCI format 3 and DCIformat 3A in the PDCCH region, and detects control channels that coverDCI format 2B in the E-PDCCH region.

In addition, the configuration information may be sent by the basestation to the user equipment through user equipment-specific(UE-specific) signaling or cell-specific (cell-specific) signaling.

In another specific embodiment, if the search space type differs betweenthe control channel of the first type and the control channel of thesecond type, the search space corresponding to the control channeldetected by the user equipment in the PDCCH region is different from thesearch space corresponding to the control channel detected by the userequipment in the E-PDCCH region. Specifically, the control channel ofthe first type detected by the user equipment in the PDCCH region may bea control channel in the common search space, and the control channel ofthe second type detected in the E-PDCCH region may be a control channelin the user-specific search space of the user equipment.

An embodiment of the present invention provides a method for sending acontrol channel, applied to control channel sending performed by a basestation when the base station schedules a user equipment. The method inthe embodiment of the present invention is performed by the basestation. As shown in FIG. 6, the method includes the following steps:

Step 201: Send scheduling information over a control channel of a firsttype within a physical downlink control channel PDCCH region.

Step 202: Send scheduling information over a control channel of a secondtype within an evolved physical downlink control channel E-PDCCH region.

At least one of attributes varies between the control channel of thefirst type and the control channel of the second type. The multipleattributes include: an aggregation format of the control channel, aformat of signaling transmitted over the control channel, a search spacetype of the control channel, and so on.

If the aggregation format of the control channel of the first type isdifferent from the aggregation format of the control channel of thesecond type, both the control channel of the first type and the controlchannel of the second type may cover at least one aggregation format ofcontrol channels Therefore, the base station sends, in the PDCCH regionand in the E-PDCCH region, user equipment scheduling information byusing control channels of completely or partially different controlchannel element combinations, where the different control channelelement combinations include completely or partially different numbersof integral control channel elements (aggregation level) and/or formats(such as sizes) of the control channel elements; and the size of theresources of the aggregation formats covered by the control channel ofthe first type transmitted over the base station in the E-PDCCH regionis not smaller than the size of the resources of the aggregation formatscovered by the control channel of the second type sent in the PDCCHregion.

If the format of signaling transmitted over the control channel of thefirst type is different from the format of signaling transmitted overthe control channel of the second type, that is, if the format ofsignaling for the control channel of the first type to transmitscheduling information is different from the format of signaling for thecontrol channel of the second type to transmit scheduling information,the base station sends, in the PDCCH region and the E-PDCCH region, userequipment scheduling information by using control channels of differentDCI formats. Specifically, the DCI format may be an uplink schedulingUL_grant control signaling format, or a downlink scheduling DL_grantcontrol signaling format, or the like. For example, the DCI format ofdownlink control information transmitted over the control channel of thefirst type in the PDCCH region is an uplink scheduling UL_grant controlsignaling format, and the DCI format of downlink control informationtransmitted over the control channel of the second type in the E-PDCCHregion is a downlink scheduling DL_grant control signaling format; or,the DCI format of downlink control information transmitted over thecontrol channel of the first type in the PDCCH region is a downlinkscheduling DL_grant control signaling format, and the DCI format ofdownlink control information transmitted over the control channel of thesecond type in the E-PDCCH region is an uplink scheduling UL_grantcontrol signaling format.

If the search space type differs between the control channel of thefirst type and the control channel of the second type, the base stationmaps the control channels in the PDCCH region and the control channelsin the E-PDCCH region to different search spaces, for example, to acommon search space and a user-specific search space, or the like.

It should be noted that, if the two types of DCI formats are equal insize at the time of sending the scheduling information, the base stationtransmits scheduling information of one type of DCI formats over thecontrol channel of the first type in the PDCCH region, and transmitsscheduling information of the other type of DCI formats over the controlchannel of the second type in the E-PDCCH region.

Understandably, when sending the user equipment scheduling information,the base station needs to send a downlink subframe that includes thePDCCH region and the E-PDCCH region to the user equipment, but the userequipment does not know compositions of the PDCCH region and the E-PDCCHregion of the user equipment in the downlink frame, and needs to performblind detection. The method of the blind detection has been described inthe embodiment shown in FIG. 1, and is not repeated here any further.

As can be seen, in the embodiment of the present invention, the basestation carries the scheduling information of the user equipment in theR11 system in both the PDCCH region and the E-PDCCH region, and thetypes of the sent control channels in both the PDCCH region and theE-PDCCH region differs. In this way, resources of two regions areavailable to the user equipment in the R11 system, and the userequipment needs to detect control channels of different types within thePDCCH region and the E-PDCCH region respectively. Therefore, the userequipment detects only the control channel of the first type in thePDCCH region, and detects the control channel of the second type in theE-PDCCH region. In this way, compared with the fact that in the systemof a non-evolved release, the user equipment needs to detect controlchannels of all possible types, the number of control channel detectionsdoes not increase.

In a specific embodiment, the base station may configure the types ofcontrol channels to be detected by the user equipment. Specifically, thebase station may send configuration information to the user equipment,where the configuration information is used to instruct the userequipment to detect the control channel of the first type in thephysical downlink control channel PDCCH region, and detect the controlchannel of the second type in the evolved physical downlink controlchannel E-PDCCH region. In addition, the base station may send theconfiguration information to the user equipment through userequipment-specific UE-specific signaling or cell-specific cell-specificsignaling.

An embodiment of the present invention provides a user equipment. Theuser equipment is a user equipment of an R11 system, and its structuraldiagram is shown in FIG. 7. The user equipment includes:

a first detecting unit 10, configured to detect a control channel of afirst type within a physical downlink control channel PDCCH region; and

a second detecting unit 11, configured to detect a control channel of asecond type within an evolved physical downlink control channel E-PDCCHregion, where the control channel of the first type is different fromthe control channel of the second type. Specifically, at least one ofmultiple attributes varies between the control channel of the first typedetected by the first detecting unit 10 and the control channel of thesecond type detected by the second detecting unit 11. The multipleattributes include: an aggregation format of the control channel, aformat of signaling transmitted over the control channel, a search spacetype of the control channel, and so on.

Understandably, if the aggregation formats differ between the controlchannel of the first type and the control channel of the second type,the aggregation formats covered by the control channels detected by thefirst detecting unit 10 in the PDCCH region are fully or partlydifferent from the aggregation formats covered by the control channelsdetected by the second detecting unit 11 in the E-PDCCH region, whichincludes that the aggregation levels of the control channels and/or theformats of the control channel elements are completely or partiallydifferent. When the aggregation formats covered by the control channelof the first type detected are partly different from the aggregationformats covered by the control channel of the second type detected, thesum of the numbers of detections of the control channels respectively bythe first detecting unit 10 and the second detecting unit 11 is notgreater than the preset number of detections. Moreover, the size of theresources of the aggregation formats covered by the control channel ofthe second type detected by the second detecting unit 11 in the E-PDCCHregion is not smaller than the size of the resources of the aggregationformats covered by the control channel of the first type detected by thefirst detecting unit 10 in the PDCCH region.

If the format of signaling transmitted over the control channel of thefirst type is different from the format of signaling transmitted overthe control channel of the second type, the control signaling format DCIformat of the downlink control information transmitted over the controlchannel of the first type detected by the first detecting unit 10 isdifferent from the DCI format of the downlink control informationtransmitted over the control channel of the second type detected by thesecond detecting unit 11. Specifically, the DCI format may be an uplinkscheduling UL_grant control signaling format, or a downlink schedulingDL_grant control signaling format, or the like.

If the search space type differs between the control channel of thefirst type and the control channel of the second type, the firstdetecting unit 10 may detect the control channel of the first type inthe PDCCH region in a common search space, and the second detecting unit11 may detect the control channel of the second type in the E-PDCCHregion in a user-specific search space of the user equipment.

It should be noted that the detection performed by the first detectingunit 10 and the detection performed by the second detecting unit 11 donot occur in definite order, and may occur concurrently or sequentially.

In the user equipment in the embodiment of the present invention, thefirst detecting unit 10 and the second detecting unit 11 need to detectcontrol channels in the PDCCH region and the E-PDCCH regionrespectively, so that resources of the two regions are available to theuser equipment in the R11 system. Because the control channel of thefirst type is different from the control channel of the second type, theuser equipment detects control channels of only one type in the PDCCHregion, and detects control channels of the other type in the E-PDCCHregion. In this way, compared with the fact that in the system of anon-evolved release, the user equipment needs to detect control channelsof all possible types, the number of control channel detections does notincrease.

In a specific embodiment, the user equipment in the embodiment of thepresent invention may further include a configuring unit 12, configuredto receive configuration information sent by a base station, where theconfiguration information is used to indicate the control channels ofthe first type and the second type.

In addition, the configuration information may be sent by the basestation to the user equipment through user equipment-specific(UE-specific) signaling or cell-specific (cell-specific) signaling.

An embodiment of the present invention provides a base station, astructural diagram is shown in FIG. 8. The base station includes:

a first sending unit 20, configured to send scheduling information overa control channel of a first type within a physical downlink controlchannel PDCCH region; and

a second sending unit 21, configured to send scheduling information overa control channel of a second type within an evolved physical downlinkcontrol channel E-PDCCH region.

At least one of multiple attributes varies between the control channelof the first type that carries the scheduling information sent by thefirst sending unit 20 and the control channel of the second type thatcarries the scheduling information sent by the second sending unit 21.The multiple attributes include: an aggregation format of the controlchannel, a format of signaling transmitted over the control channel, asearch space type of the control channel.

If the aggregation formats differ between the control channel of thefirst type and the control channel of the second type, the controlchannel element combination mode used by the first sending unit 20 tosend the user equipment scheduling information in the PDCCH region isdifferent from the control channel element combination mode used by thesecond sending unit 21 to send the user equipment scheduling informationin the E-PDCCH region, where the difference includes difference of theaggregation levels of the control channel elements and/or the formats ofthe control channel elements.

If the format of signaling transmitted over the control channel of thefirst type is different from the format of signaling transmitted overthe control channel of the second type, the control signaling formatused by the first sending unit 20 to send the user equipment schedulinginformation in the PDCCH region is different from the control signalingformat used by the second sending unit 21 to send the user equipmentscheduling information in the E-PDCCH region, where the DCI format isspecifically an uplink scheduling UL_grant control signaling format or adownlink scheduling DL_grant control signaling format, or the like. Inaddition, if the two types of DCI formats are equal in size, the firstsending unit 20 and the second sending unit 21 transmit downlink controlinformation of one type of DCI formats over the control channel of thefirst type in the PDCCH region, and transmit downlink controlinformation of the other type of DCI formats over the control channel ofthe second type in the E-PDCCH region, respectively.

If the search space type differs between the control channel of thefirst type and the control channel of the second type, the first sendingunit 20 and the second sending unit 21 may map the PDCCH region and theE-PDCCH region to different search spaces, for example, to a commonsearch space or a user-specific search space, or the like.

As can be seen, in the base station in the embodiment of the presentinvention, the first sending unit 20 and the second sending unit 21 sendthe scheduling information of the user equipment in the R11 system inthe PDCCH region and the E-PDCCH region respectively, and the type ofthe used control channel differs. In this way, resources of two regionsare available to the user equipment in the R11 system, and the userequipment needs to detect control channels of different types within thePDCCH region and E-PDCCH region respectively. Therefore, the userequipment detects control channels of only one type in the PDCCH region,and detects control channels of the other type in the E-PDCCH region. Inthis way, compared with the fact that in the system of a non-evolvedrelease, the user equipment needs to detect control channels of allpossible types, the number of control channel detections performed bythe user equipment does not increase.

In a specific embodiment, the base station in this embodiment mayfurther include a configuration sending unit 22, configured to sendconfiguration information to the user equipment, where the configurationinformation is used to instruct the user equipment to detect the controlchannel of the first type in the physical downlink control channel PDCCHregion and detect the control channel of the second type in the evolvedphysical downlink control channel E-PDCCH region.

Moreover, the configuration information may be sent by the configurationsending unit 22 of the base station to the user equipment through userequipment-specific UE-specific signaling or cell-specific cell-specificsignaling.

An embodiment of the present invention provides a system for receivingand sending a control channel, including a base station and a userequipment. The base station is configured to send a downlink subframe tothe user equipment, and its structure is shown in FIG. 8; and the userequipment is configured to perform blind detection when receiving adownlink subframe, and its structure is shown in FIG. 7.

The methods performed by the base station and the user equipment maycorrespond to the embodiments shown in FIG. 6 and FIG. 2 respectively,and are not repeated here any further.

A person of ordinary skill in the art may understand that all or a partof the steps of the methods in the foregoing embodiments may beimplemented by a program instructing relevant hardware. The program maybe stored in a computer readable storage medium, and the storage mediummay include a read-only memory (ROM), a random access memory (RAM), amagnetic disk, or an optical disk or the like.

Methods and apparatuses for receiving and sending a control channel thatare provided in the embodiments of the present invention are introducedin detail in the foregoing. In this specification, specific examples areused for illustrating principles and implementation manners of thepresent invention. The foregoing descriptions of the embodiments aremerely used to help understand the methods and core ideas of the presentinvention. Meanwhile, a person of ordinary skill in the art may makevarious modifications to the specific implementation manners andapplication scopes according to the idea of the present invention. Inconclusion, the content of the specification shall not be construed as alimitation to the present invention.

What is claimed is:
 1. A method for receiving a control channel,comprising: detecting, by a terminal device, a control channel of afirst type within a physical downlink control channel (PDCCH) region ina downlink subframe in a carrier; and detecting, by the terminal device,a control channel of a second type within an evolved physical downlinkcontrol channel (E-PDCCH) region in the downlink subframe containing thePDCCH region, wherein the control channel of the first type is differentfrom the control channel of the second type; wherein the control channelof the first type is a control channel of a common search space and thecontrol channel of the first type is not a control channel of a searchspace specific to the terminal device, and the control channel of thesecond type is a control channel of the search space specific to theterminal device and the control channel of the second type is not acontrol channel of the common search space, and wherein the commonsearch space is used to transmit control information common for terminaldevices in a cell, and the search space specific to the terminal deviceis used to transmit scheduling indication signaling of uplink ordownlink data transmission of the terminal device.
 2. The methodaccording to claim 1, wherein: a sum of the number of detections of thecontrol channel of the first type in the PDCCH region and the number ofdetections of the control channel of the second type in the E-PDCCHregion is not greater than a preset number of detections.
 3. The methodaccording to claim 1, wherein: at least one aggregation format coveredby the control channel of the first type is different from aggregationformats covered by the control channel of the second type.
 4. The methodaccording to claim 3, wherein at least one of an aggregation leveland/or at least one of a format of control channel elements variesbetween the control channel of the first type and the control channel ofthe second type.
 5. The method according to claim 3, wherein: a size ofresources of the aggregation formats covered by the control channel ofthe second type is not smaller than a size of resources of theaggregation formats covered by the control channel of the first type. 6.The method according to claim 1, wherein a downlink control informationformat (DCI format) transmitted over the control channel of the firsttype is different from a DCI format transmitted over the control channelof the second type.
 7. The method according to claim 6, wherein the DCIformat transmitted over the control channel of the first type is anuplink scheduling (UL_grant) control signaling format, and the DCIformat transmitted over the control channel of the second type is adownlink scheduling (DL_grant) control signaling format; or the DCIformat transmitted over the control channel of the first type is aDL_grant control signaling format, and the DCI format transmitted overthe control channel of the second type is an UL_grant control signalingformat.
 8. The method according to claim 6, wherein: a size of the DCIformat transmitted over the control channel of the first type is thesame as a size of the DCI format transmitted over the control channel ofthe second type.
 9. The method according to claim 1, wherein: beforedetecting the control channel in the PDCCH region and the E-PDCCHregion, the method further comprises: receiving, by the terminal device,configuration information from a base station, wherein the configurationinformation indicates the control channel of the second type.
 10. Themethod according to claim 9, wherein: the configuration information iscarried on signaling specific for the terminal device.
 11. An apparatus,comprising a non-transitory computer readable storage medium includingexecutable instructions; and a processor; wherein the executableinstructions, when executed by the processor, cause the processor to:detect a control channel of a first type within a physical downlinkcontrol channel (PDCCH) region in a downlink subframe in a carrier; anddetect a control channel of a second type within an evolved physicaldownlink control channel (E-PDCCH) region in the downlink subframecontaining the PDCCH region, wherein the control channel of the firsttype is different from the control channel of the second type; whereinthe control channel of the first type is a control channel of a commonsearch space and the control channel of the first type is not a controlchannel of a search space specific to the terminal device, and thecontrol channel of the second type is a control channel of the searchspace specific to the terminal device and the control channel of thesecond type is not a control channel of the common search space, andwherein the common search space is used to transmit control informationcommon for terminal devices in a cell, and the search space specific tothe terminal device is used to transmit scheduling indication signalingof uplink or downlink data transmission of the terminal device.
 12. Theapparatus according to claim 11, wherein: at least one aggregationformat covered by the control channel of the first type is differentfrom aggregation formats covered by the control channel of the secondtype.
 13. The apparatus according to claim 11, wherein a downlinkcontrol information format (DCI format) transmitted over the controlchannel of the first type is different from a DCI format transmittedover the control channel of the second type, wherein the DCI formattransmitted over the control channel of the first type is an uplinkscheduling (UL_grant) control signaling format, and the DCI formattransmitted over the control channel of the second type is a downlinkscheduling (DL_grant) control signaling format; or the DCI formattransmitted over the control channel of the first type is a DL_grantcontrol signaling format, and the DCI format transmitted over thecontrol channel of the second type is an UL_grant control signalingformat.
 14. A terminal device, comprising: a transceiver, and aprocessor communicatively connected with the transceiver, wherein theprocessor is configured to: detect a control channel of a first typewithin a physical downlink control channel (PDCCH) region in a downlinksubframe in a carrier; and detect a control channel of a second typewithin an evolved physical downlink control channel (E-PDCCH) region inthe downlink subframe containing the PDCCH region, wherein the controlchannel of the first type is different from the control channel of thesecond type; wherein the control channel of the first type is a controlchannel of a common search space and the control channel of the firsttype is not a control channel of a search space specific to the terminaldevice, and the control channel of the second type is a control channelof the search space specific to the terminal device and the controlchannel of the second type is not a control channel of the common searchspace, and wherein the common search space is used to transmit controlinformation common for terminal devices in a cell, and the search spacespecific to the terminal device is used to transmit schedulingindication signaling of uplink or downlink data transmission of theterminal device.
 15. The terminal device according to claim 14, wherein:at least one aggregation format in the aggregation formats covered bythe control channel of the first type is different from aggregationformats covered by the control channel of the second type.
 16. Theterminal device according to claim 15, wherein at least one of anaggregation level and/or at least one of a format of control channelelements varies between the control channel of the first type and thecontrol channel of the second type.
 17. The terminal device according toclaim 15, wherein: a size of resources of the aggregation formatscovered by the control channel of the second type is not smaller than asize of resources of the aggregation formats covered by the controlchannel of the first type.
 18. The terminal device according to claim14, wherein a downlink control information format (DCI format)transmitted over the control channel of the first type is different froma DCI format transmitted over the control channel of the second type.19. The terminal device according to claim 18, wherein the DCI formattransmitted over the control channel of the first type is an uplinkscheduling (UL_grant) control signaling format, and the DCI formattransmitted over the control channel of the second type is a downlinkscheduling (DL_grant) control signaling format; or the DCI formattransmitted over the control channel of the first type is a DL_grantcontrol signaling format, and the DCI format transmitted over thecontrol channel of the second type is an UL_grant control signalingformat.
 20. The terminal device according to claim 18, wherein: a sizeof the DCI format transmitted over the control channel of the first typeis the same as a size of the DCI format transmitted over the controlchannel of the second type.
 21. The terminal device according to claim14, wherein: the transceiver is configured to receive configurationinformation from a base station, wherein the configuration informationindicates the control channel of the second type.
 22. The terminaldevice according to claim 21, wherein: the configuration information iscarried on signaling specific for the terminal device.
 23. The terminaldevice according to claim 14, wherein: a sum of the number of detectionsof the control channel of the first type in the PDCCH region and thenumber of detections of the control channel of the second type in theE-PDCCH region is not greater than a preset number of detections.